DC monuments vandalized over the weekend

US Park Police discovered several instances of freaky, conspiratorial graffiti at the Lincoln Memorial, the Washington Monument and the World War II Memorial over President's Day weekend, officials said.

She says the graffiti on the Washington Monument references President John F. Kennedy's assassination and 9/11.

"Somebody appears to have - with Sharpie or magic marker - tagged similar messages at the Lincoln Memorial, the Washington Monument and the World War II Memorial", Mike Litterst, spokesman with the National Park Service, told NBC Washington.

A monument preservation crew has done a first cleaning at the Lincoln Memorial, and the clean-up at the three sites will take a few weeks, Litterst said. And one said "blood test is a lie" and "get second opinion" for leukemia, cancer and HIV.

U.S. Park Police and NPS officials will update media at 11 a.m. with details on the damage, the status of the investigation, and what's being done to remove the graffiti.

He said the timing of the incidents were "completely disheartening".

"We understand that there was quite a crowd here Saturday night who may have seen something", Sgt. Anna Rose, a spokeswoman for the U.S. Park Police, said at the news conference.